I had the same problem with mine at the Grand. I went and talked to Diann Pennington. What it ended up being was the trigger wasn't fitting in the reciver tight enough. The vibration from the fist shot was causing the sear for the second shot to give, causing a double. I would contact Diann and tell her whats happening. Most likely she'll have you send it to her so she can install a "squish pin". That will tighten up the trigger, and eliminate the vibration. It worked on mine. (P.S. Mine is a pull/pull, I'm not for sure if it's different from a release/pull or not, but I don't think it is.)

Send the trigger back. It should not be happening and you shouldn't have to change anything. Sounds like the 2nd sear is letting go at the same time as the 1st. If you don't get it fixed it will screw with your brain and for what that trigger costs you shouldn't be having any problems.

Tex shooter,
I had the same problem with my precision trigger(double release) and the problem was solved by having precision triggers install a longer cocking cam.
They have 3 or 4 different lenghts available.
Jack Kostkas